Method of applying an aqueous size to strands formed of glass filaments and product produced thereby



Jan. 26, 1965 J. B. LOVELACE ETAL 3,167,468

METHOD OF APPLYING AN AQUEOUS SIZE TO STRANDS FORMED OF GLASS FILAMENTSAND PRODUCT PRODUCED THEREBY Filed May 25, 1961 2 Sheets-Sheet l 1965 J.B. LOVELACE ETAL 3,167,468

METHOD OF APPLYING AN AQUEOUS SIZE TO STRANDS FORMED OF GLASS FILAMENTSAND PRODUCT PRODUCED THEREBY Fqlled May 25, 1961 2 Sheets-Sheet 2 YARDScmvus NO sanos 3 ZIS 4 B Mu/fl 5 P4775250 A "aw/5r United States PatentC 3,167,468 METHGD 9F APPLYING AN AQUEGUS SEZE T STRANDS FGRMED 0F GLASSFELAMENTS AND PRDDUQT PRQDUCED THEREEY Joe B. Lovelace, Eilenboro, andWiliiarn E. Patterson, Kings Mountain, N.C., assignors to PittsburghPlate Glass Company, Pittsburgh, Pa a corporation of Pennsylvania FiledMay 25, 196i, Ser. No. 112,631 10 Qiaims. ((Jl. 161-475) This inventionrelates to a process for preparing glass fibers and it has particularrelation to the application of a size to continuous filament glass fiberstrand during the formation of the strand.

In the production of continuous filament glass fiber strand, a number ofindividual glass filaments are drawn from an electrically heated,platinum alloy bushing containing a molten supply of the glass. Theglass passes through tips which define orifices in the bottom of thebushing and forms inverted cones of glass at the ends of the tips.individual filaments are drawn from the cones of glass at a high rate ofspeed, i.e., 5,000 to 20,000 feet per minute, and are grouped into astrand as they pass over a suitable guide. The strand is thereafterwound on a rapidly rotating forming tube.

There is no twist in the strand as it is thus formed and an aqueous sizecomposed of an aqueous dispersion of a binder and a lubricant, such asdextrinized corn starch and a vegetable oil, is applied to theindividual filaments prior to the tie they are grouped into the strandand wound on the tube in order to bond them together and maintain theintegrity of the strand. The strand is wound on the tube with a slighttraverse so that succeeding turns cross each other at an angle ratherthan being parallel to each other so the strand can be more easilyremoved from the tube.

One problem which occurs in the manufacture of continuous filamentstrand in this manner is that of size strand forming package dries onthe forming tube, the

water moves from the inside of the forming package next to the tube tothe outside of the forming package. This movement of the watercarrieswith it some of the starch and oil of'the size so that the strand in'theoutside layers of the package has a much higher size solids content thanthe strand in the layers beneath the surface.

Size migration creates a number of problems in subsequent fabrication ofthe strand. In twisting, plying, warpingyquilling and weaving of glassfiber yarn there are a number of winding and unwinding operations wherethe tension exerted on the yarn is important. The tension exerted on theyarn during these operations must be relatively constant. if the tensionon the yarn is uneven during these operations, the individual filamentsmaking up the yarn are likely to be broken and produce fuzzy yarn. Fuzzyyarn clogs up the fabricating equipment and causes yarn breakout. Uneventension on the yarn can be created by non-uniform size content on theyarn through out its length. Thus, it is desired that the size contenton the yarn be uniform throughout its length.

Another fabricating operation where uneven size content on the yarn istroublesome is in the process of texturing yarn. Textured yarns arethose continuous fila- Edfilidd ice ment yarns which have been bulked byan air jet such as described in US. Patent No. 2,783,699. The sizecontent of the yarn which is textured determines the resistance of theyarn to being textured or bulked by the air jet. A variation in sizecontent along the length of the yarn results in a variation in thedegree of bulking. Any variation in the degree of bulking of the yarnshows up in the fabric and may be serious enough to result in rejectionof the piece of goods.

An additional problem due to size migration is encountered when wovenfabrics are heat treated. The strand with the higher size solids contentshows up differently than the strand with the lower size solids contentwhen the twisted strand is woven into a fabric and the fabric is heatedto remove the size and set the fibers in the fabric. This heating isconducted at a temperature of about 1200 to 1400 F. for 30 to 40 secondsand is sufficient to volatilize the solids and remove them from thefabric and to soften the fibers in the fabric to set them in their newposition. This process is described in greater detail in US. Patent No.2,845,364. After the heat treatment, the strand from the outside of theforming package which originally had the higher size solids contentsshows up as a band in the fabric which reflects light to a differentextent than the rest of the fabric. Sometimes this band exhibits a moireefiect. This results in an imperfection in the fabric which is ofsufiicient magnitude to cause rejection of the piece of goods. It is notknown exactly what causes the difference in the yarn in the fabric;however, it is believed that it may be due to incomplete re moval of thesize or it may be due to a difference in the orientation of theindividual filaments in the yarn due to the increased heating activitywhich occurs in the areas of increased size solids content when thefabric has been sufiiciently heated to remove all of the size throughoutthe fabric. In any event, this difference has definitely been noted andhas been a cause for serious concern with the yarn manufactue-rs andweavers. The above defects have also occurred in fabrics woven withtextured, continuous filament glass yarns.

As can be surmised from the description above concerning the defects inwoven fabrics caused by size migra tion, this problem has been a mostserious problem and has required drastic steps to overcome it. Thesesteps have involved the stripping or running off of the strand on theoutside of the forming package to remove that portion of the formingpackage which contains strand having a higher size content than theremainder of the package. This represents a substantial loss in theproduction of strand and also requires a costly and undesirableintermediate step between the forming and twisting of the strand.

Apart from the problems which are created by size migration,conventional starch-oil sizes have been ditilcult to texturize by theair jet process mentioned above. The starch binder has been observed topowder and be blown off of the yarn being subjected to the jet. Thiscreates an atmosphere problem which is annoying to the operators. italso clogs the texturing jet and results in uneven texturing of theyarn. Deposits of starch build up. in the jet, and reduce the texturingeffect as they are buiit up; The back pressure in the jet then builds upuntil finally the pressure is sufficient to blow out all of the starchaccumulation at once and the complete texturing effect is again resumed.This results in a chattering effect in the jet and uneven texturing ofthe yarn passing through the jet.

It is, therefore, an object of this invention to provide an aqueous sizewhich can be easily applied to glass fiber strand during its formationin uniform, controlled amounts and whose non-aqueous constituents willnot migrate in the strand forming package upon drying of the package onthe forming tube. It is a further object of the invention to providesuch a size which will permit the strand to be twisted, uniformlytextured if desired, quilled or warped, and woven into cloth withuniform tension and with a minimum of broken filaments in these variousfabricating operations. It is also an object of the invention to providean aqueous size whose solids constituents can be readily and completelyremoved from a woven fabric by the conventional heat treatments whichare applied to fabrics to remove the size ingredients and set the fibersin the fabric.

The objects of the invention are achieved by the application to a strandduring its formation of an aqueous size containing as the binderingredient a starch-amine reaction product. The size also contains otheringredients such as a vegetable oil as a lubricant, a fungicide such asformaldehyde, a softening agent and a wetting agent. Small amounts ofadditional film forming ingredients other than starch may be included,such as for example, gelatin or polyvinyl alcohol to make a more durablestrand. The term starch includes any amylaceous substance such asuntreated starch, as Well as starch derivatives including dextrinized,hydrolyzed, oxidized, esterified and etherified starches still retainingamylaceous material. The starches may be derived from any sourcesincluding corn, wheat, potato, tapioca, waxy maize, sago or rice.

The starch-amine reaction products which are useful in the invention aremade by reacting starch with an esterification or etherification reagentwhich will serve to introduce an amine group to the starch. Said reagentmay be selected from the group of nitrogen containing compoundsconsisting of amino alkyl anhydrides, alkyl imines, alkyl epoxides andalkyl amino halides, as Well as the corresponding compounds containingaryl groups in addition to the alkyl groups. All of the various types ofreagents listed herein have the common characteristic of reacting withhydroxyl groups in the starch to introduce an ester or ether linkage andthereby introduce an amine radical into the starch.

Representative examples of specific reagents for the purpose of makingsuch starch derivatives include ethylene imine; propylene imine; isatoicanhydride; quinolinic anhydride; b-diethyl amino ethyl chloride; bmethylamino isopropyl chloride; b-dimethyl amino ethyl chloride; 3-diethylamino 1,2-epoxypropane; 3-dibutyl amino 1,2-epoxypropane;Z-bromo-S-diethyl amino pentane hydrobromide;N-(2,3-epoxypropyl)-piperidine; and N,N-(2,3-epoxypropyl) methylaniline. The various halides (eg. chloro-, bromo-, etc.) can be usedinterchangeably. In the above reagents, where the free amines have beenindicated (e.g. b-diethyl amino ethyl chloride), one can also use thehydrochloride or other salts of these reagents (e.g. b-diethyl aminoethyl chloride hydrochloride). In fact it is ordinarily preferred to usethe salts since these are often less toxic and more convenient tohandle. The hydrochloride moiety takes no part in the reaction. It Willbe seen that besides the alkyl, aryl and aralkyl types, the reagents mayalso include those containing cyclic groups. Therefore when reference ismade to the alkyl, aryl and'aralkyl groups, it will be understood thatthe cyclic reagents are equivalents of these types. The starch-aminereaction product may also be treated so as to result in the quaternaryammonium salt.

The starch-amine reaction products can be produced by known methods suchas those set forth in US. Patents Nos. 2,813,093 and2,946,70 5. Inmaking the starchamine reaction products, the starch is preferablytreated with any of the previously described reagents in the presence ofan alkaline medium. This is accomplished by suspending the starch inwater, to Which has been added (either before or after the addition ofthe starch) suflicient base, such as alkali metal hydroxide, alkalineearth hydroxide, quaternary ammonium hydroxide, or the like,

to maintain the mixture in an alkaline state during the reaction. Therequired amount of the amine reagent is then added, agitation beingmaintained until the desired reaction is complete. Heat may be appliedif desired in order to speed the reaction since the usual timetemperature relation applies. The proportion of etherification toresterification reagent used varies with the particular reagent chosen(since they vary in reactivity and reaction efficiency) and the degreeof substitution desired. The amine-starch reaction product may contain0.5 to 30 percent by weight of an amine introducing reagent based on theweight of the starch.

The starch-amine reaction product can be prepared in either gelatinizedor ungelatinized form. In order to avoid gelatinization of the starchduring the reaction with the amine in those cases where the degree ofalkalinity or heat is such as would ordinarily cause gelatinization tooccur, a gelatinization retarding chemical, such as sodium sulfate, isadded to the starch-alkali-water-reagent mixture.

The starch-amine reaction product as thus produced is broadly describedby the following structural formula:

group consisting of substituted alkyl, hydroxyl alkyl, acyl or aroylradicals,'and' each of R and R is a radical selected from the groupconsisting ofhydro'gen, alkyl or aralkyl radicals. If the derivative isin the form of the salt, or if it is in the form of the quaternary salt,the formula is then represented as follows:

Ilh

wherein X is again starch, R is again a radical selected from the groupconsisting of substituted alkyl, hydroxyl alkyl, acyl or aroyl radicals,and each of R and R is 'a radical selected from the group consisting ofhydrogen, alkyl or aralkyl radicals, and where R, is hydrogen or analkyl group and Y is a chloride, bromide or an' iodide radical.

Examples of the glass fiber strand size are set forth below: 1

Example I The following table lists various sizing formulations whichare useful forthe practice of the invention wherein the starch-aminereaction product is an alkyl amino halide salt resulting from thereaction of corn starch with b-diethyl amino ethyl chloridehydrochloride.

Parts by Weight (grams) Ingredient Starch-amine Formaldehyde, cc. 17 1717 17 17 17 17 pH 4.0 4.0 4.0 3.9 4.5 3.5 3.3 5.0 Percent s01ids 6.417.17 6.27 5.47 6.0 5.15 4.59 6.0 Percent application 0.97 1.02 1.16 0.841.04

The above formulations are given in the amounts required for making fivegallon mixtures of the size. All of the amounts are in grams asindicated in the heading for the table with the exception of theformaldehyde which is set forth in cubic centimeters. The starch-aminereaction product is prepared by reacting corn starch with b-diethylamino ethyl chloride hydrochloride in the following manner. Four poundsof sodium hydroxide are dissolved in 150 pounds of water and 50 poundsof sodium sulfate are added. Agitation is continued until the reagentshave wherein X is a starch, R is a radical selected from the dissolvedand 100 pounds of corn starch are then added with continued agitation.When the suspension is uniform, there is added a solution of 4 pounds ofb-diethyl amino ethyl chloride hydrochloride and 25 pounds of Water.Agitation is maintained for 24 hours, at which time enough dilutehydrochloric acid solution is added to adjust the pH to approximately 3.The starch product is then filtered, washed thoroughly with water anddried in the form of a powder. The Pureco oil in the formulations is apartially hydrogenated vegetable oil made by the Capital City ProductsCompany. The Tween 81 is a wetting agent and is an ethylene oxidederivative of a sorbital ester made by Atlas Powder Company. Cation Xis. I

a textile softener and is an alkyl imidazoline reaction product oftetraethylene pcntamine and stearic acid as made by the Onyx Oil andChemical Company.

The size is prepared by first adding 2 /2 gallons of water to a mixingkettle. The starch-amine reaction product is then added to the water toform a slurry and the pH of the slurry is adjusted to 3.5 plus or minus0.2 with acetic acid. The slurry is heated to 200 F. and held at thistemperature for about 15 minutes in order to gelatinize the starch-aminereaction product. The gelatinized starcharnine reaction product in theaqueous diluent is then cooled to 160 F. The Pureco oil is added next.The Pureco oil is a solid material having the consistency of lard and itis first melted and then emulsified with water, Tween 81 and a smallamount (200 to 400 cubic centimeters) of the gelatinized starch-aminereaction product before it is added to the main portion of thegelatinized starch-amine reaction product. Cation X, dispersed in aboutgallon of water, is next added to the size and formaldehyde isthereafter added. The size as thus prepared is adjusted to a pH of about3.3 to 5 by the addition of acetic or hydrochloric acid. The size has aviscosity of about 1 to 20 centipoises at 20 C. and a solids content ofabout 4 to 7.5 percent by weight of the size as shown in the examples.

When glycerine is employed in the size, it is added prior to theaddition of the Pureco oil. This is accomplished by just pouring it intothe cooked starch-amine reaction product and mixing it therewith. Thegelatin is dispersed in water at 140 F. with vigorous agitation and italso is added to the gelatinized starch-amine reaction product prior tothe addition of the Pureco oil. Elvanol (polyvinyl alcohol sold by duPont) is dissolved inwater at 140 F. and is added in the sizepreparation right after the Pureco oil.

Example 11 The following is an example of a size formulation utilizin areaction product of starch and an alkylene imine. The hydroxyethyl etherof corn starch is reacted in the manner described in Example I with 30percent by weight-of ethylene imine based upon the weight of, thehydroxyethyl ether of corn starch. A size is prepared in the same manneras in Example I utilizing the following ingredients:

Ingredient: Parts by Weight Starch-ethylene irnine reaction product 800.Hydrogenated vegetable oil 410.5. Wetting agent (T-ween 81) 40.9.Softener (Cation X) 44.3. Glycerine 80.0. Formaldehyde 17 cubiccentimeters per gallon size mix.

Example III A size utilizing the reaction product of corn starch and 5percent by weight of propylene imine based upon the weight of the cornstarch is prepared in the same manner as set forth in Example ll.

6 Example IV The following is an example of a size formulation utilizinga reaction product of starch and an alkyl amino epoxide. Sago starch isreacted in the same manner as set forth in Example I with 10 percent byweight of 3- dibutyl amino 1,2-epoxy propane based upon the weight ofthe sago starch. The size is prepared in the same manner as described inExample I utilizing the following ingredien-ts:

Ingredient: Parts by weight Sago starch-epoxide reaction product 780.Pureco oil 322. Tween 81 32. Cation X 68.

Gelatin 5. Polyvinyl alcohol 7. Formaldehyde 17 cubic centimeters per 5gallon size mix.

Example V The following is an example of a size formulation utilizing areaction product of starch and an amino alkyl anhydride. Potatostarch isreacted in'the same manner as set forth in Example I with 20 percent byweight of isatoic anhydride based'upo-n the weight of the potato starch.The size is prepared in the same manner as described in Example Iutilizing the following ingredients:

Example VI A size utilizing the reaction product of corn starch and 10percent by weight of quinoline anhydr-ide based upon the weight of thecorn starch is prepared in the same mannor as set forth in Example V.

Example VII The following is an example of a size formulation utilizinga reaction product of starch and an alkyl amino anhydride. Tapiocastarch is reacted in the same manner as set forth in Example. I with 3percent by weight of b-dimethyl amino isoprcpyl chloride based upon theweight of the tapioca starch. The size is prepared inthe same manner asdescribed in Example I utilizing the following ingredients:

Ingredient: Parts by weight tarch-alkyl amino halide reaction product1000.

Pureco oil 308.

Tween 81 40.9. Cation X -Q 44.3.

Formaldehyde 17 cubic. centimeters per 5 gallon size Example "VIII Thefollowing is an example of a size formulation utilizing a reactionproduct of starch and an alkyl amino halide which is difierent from thatset forth in Example V. Corn starch, which is acid-converted to a degreeknown in the trade as 60 fluidity, is reacted in the same manner as setforth in Example I with 0.5 percent by weight of b-dimethyl amino ethylchloride based upon the weight of corn starch. The size is prepared inthe same manner as described in Example I utilizing the followingingredients:

Ingredient: Parts by weight Corn starch 780. Pureco oil 322.

Tween 81 32. Cation X 68.

Gelatin 5.

Polyvinyl alcohol 7. Formaldehyde 17 cubic centimeters per gallon sizemix. Example IX Potato starch is reacted with 1 percent by weight of 2-bromo-S-diethyl amino pentane hydrobromide based upon the weight of thepotato starch. The size is prepared in the same manner as described inExample I utilizing the following ingredients:

Ingredient: Parts by weight Potato starch arnino reaction product 600Pureco oil 410 'Tween 81 40.9 Cation X 88.6

Glycerine 100 Example X A starch-amine reaction product suitable for usein the invention is prepared in the manner set forth in Example I byreacting waxy maize starch with 25 percent by weight of N-(2,3epoxypropyl) piperidine based upon the weight of the waxy maize. Thesize is prepared in the same manner as described in Example I utilizingthe following ingredients:

Ingredient: Parts by weight Waxy maize 910. Pureco oil 210.

Tween 81 21. Cation X 44.

Gelatin 5. Polyvinyl alcohol 11. Formaldehyde 17 cubic centimeters per 5gallon size mix. Example XI A size utilizing the reaction product ofrice starch and 30 percent by weight of N,N-(2,3 epoxypropyl methylaniline) based upon the weight of the rice starch is prepared in thesame manner as set forth in Example X.

The size is added to the fibers during their forming while it is at anelevated temperature, i.e. 125 to 135 F for example about 130 F. This isnecessary in order to keep all of the ingredients of the size,especially the hydrogenated vegetable oil and the starch-amine reactionproduct, uniformly dispersed in the size. If the size is allowed to coolto, say for example room temperature, these ingredients tends toseparate from the size. The

method of adding the size to the strands and an analysis of the amountof size on the strand after forming and conditioning is furtherdescribed in conjunction with a description of the drawings in which:

FIG. 1 is a diagrammatic elevation of a continuous filament, glass fiberstrand operation; and

FIG. 2 is a graph illustrating the improvement of the present inventionover-the prior art with respect to size migration in the formingpackage.

In FIG. 1 of the drawing there is shown a glass melting furnace orforehearth thereof containing a supply of molten glass 11 and having anelectrically heated, platinum alloy bushing 13 attached to the bottom ofthe furnace. The bushing is provided with a series of orifices in theform of tips 14 through which the glass flows and forms in smallinverted cones 15 suspended from the bottoms of the tips 14. The tipsare usually formed in a number of rows, for example, 4 to 20 or morerows, having a great many tips in each row so that the total number oftips is about 200 to 400 or more in number.

Glass filaments 16 are pulled from the cones of glass 15 at a very highrate of speed, i.e., 5,000 to 20,000 feet per minute, and wound on therapidly rotating forming tube 18. The glass filaments are grouped into astrand 22 as they pass over the guide 24 prior to their being wound onthe tube 18. As the strand 22 is wound on the tube 18, it is rapidlytraversed by means of traverse 26. The size is applied to the individualfilaments in the strand prior to the time they pass over the guide. The

size is supplied to a reservoir 28 which has a rotating roller or belt30 mounted so as to dip into the size in the reservoir. The size istransferred from the rotating roller or belt to the filaments as thefilaments pass over the surface of the wetted roller or belt. A suitablesize applicator is shown in US. Patent No. 2,873,718.

The sizes of the present invention are easily applied to the strandduring its formation and the strand forming proceeds smoothly. Aftereach forming package containing about 3.5 pounds of 150 strand is'formed(204 filaments having a diameter such that there are 15,000 yards to thepound of strand), the forming tube and package are removed from thewinder and the end of the strand is found onthe forming package. Theforming package, containing about 9 percent by weight moisture, is thenallowed to sit in an atmosphere of about 75 to 85 F. and to percentrelative humidity for about 21 hours in order to reduce the moisturecontent on the strand to a range of about 5 to 7 percent by weight.Thereafter the strand is removed from the. forming package and twistedinto yarn. Glass fiber strand having glycerine in its size is easier toend-find than strand without the glycerine in its size. The twisting isaccomplished on conventional textile apparatus with very few brokenfilaments. The twisted yarn is.

warped or transferred onto quills for weaving, and the yarn weaves verywell with very few broken filaments. The woven material can be heattreated satisfactorily. The heat treated fabrics woven from yarn havingglycerine in its size are'slightly less brittle and more creaseresistant than heat treated fabrics woven with yarn coated with a sizenot having the glycerine.

In FIG. 2, the graph shows the size solids content of the strand in theforming package produced according to the present invention as comparedwith. the prior art. The ordinate shows the percent of size solids onthe strand after 21 hours conditioning at 45 to 55 percent relativehumidity and to degrees F. The abscissa shows the number of yards ofstrand as it is removed from the outside to the inside of the formingpackage. The dotted line represents the amount of solids of aconventional dextrinized corn starch-vegetable oil size and the solidline representsthe amounts of solids of the starch-amine reactionproduct size described in this invention "as illustrated by sizeNo. 5 ofthe table in Example I at'various points along .the strand in theforming package after conditioning as described above.

It Will be noted from this that virtually no size migraing steps, thestrand (or yarn) handles well and there are very few filaments brokenduring these fabricating steps. The yarn as sized according to themethod de scribed above is exceptionally useful for bulking by means ofthe texturing air jet described in the abovementioned patent. Theuniformity of size content on the yarn permits uniform conditions in thetexturing operation and the production of acceptable textured yarn. Thesize does not blow off of the yarn during the texturing as does theconventional dextrinized corn starch-oil size. Heat treated fabricsWoven from twisted strand formed in accordance with the presentinvention are free from the appearance defects discussed above which aredue to size migration in the strand forming package.

In various trials of the invention different amounts of the variousingredients were used in the size. Water makes up about 91 to 96 percentby weight of the size. The starch-amine reaction product makes up about4 to 7 percent by weight of the size, preferably about percent by Weightof the size. The lubricant is present in the size in amounts of 25 to 70percent by weight of the starch-amine reaction product, preferably about45 percent by weight of the starch-amine reaction product.

Various textile softeners which are equivalent to Cation X can beemployed in the size in amounts which are sufficient to provide asoftening action to the sized strand, such amounts being for example 4to 15 percent by weight of the starch-amine reaction product, preferablyabout percent by weight of the starch-amine reaction product. Suitabletextile softeners are alkyl imidazoline derivatives such as described inUS. Patents Nos. 2,200,815; 2,267,965; 2,268,273 and 2,355,837. TheCation X is an example of such a material wherein the alkyd imidazolinederivative is the reaction product of stearic acid, tetraethylenepentamine and acetic acid. A stearic acid-chromic chloride complex soldby du Pont under the tradename Quilon may serve as a softener. An acidsolubilized water dispersible stearic amide, an anhydrous acidsolubilized, water dispersible lower molecular weight fatty acid amideor an anhydrous acid solubilized polyunsaturated, lower molecular Weightfatty acid amide may be used as :a softener. Some of these softenersalso serve as wetting agents, for example the alkyl imidazolinederivatives.

Likewise, various wetting agents similar to Tween 81 may be employed inthe size in sufficient amount to permit adequate wetting of the sizingingredients to the glass surface; suitable amounts ranging from 8 to 13percent by weight of the lubricant, preferably about 10 percent byweight of the lubricant. cetyl or stearyl monoarnine hydrochloride oracetate, dodecylamine, hexadecylamine and secondary and tertiaryderivatives of the same, for example, dodecylmethylamine and saltsthereof. Quaternary ammonium compounds such as trimethyl stearyl orcetyl amonium bromides and chlorides and generally any of the aminecompounds that dissociate in water systems to provide a positive radicalcontaining a group of more than 8 and preferably 12 or more carbon atomsmay be used. These materials are cationic active substances. Non-ionicwetting agents may also be used. They are not as active as cationicwetting agents and therefore must be used in greater amounts to providethe same degree of wetting. Examples of suitable non-ionic wettingagents include polyalkylene oxide derivatives of esters, fatty acids,fatty alcohols, fatty amides, alkyl phenyl ethers and other derivatives.

A fungicide, such as formaldehyde, is usually used in sufficient amountto prevent mold attack on the starchamine reaction product. Suitableeffective amounts of the fungicide are about 3 milliliters to one gallonof the size. I

Glycerine is believed to serve as a plasticizer for the starch-aminereaction roduct. The glycerine is preferably present in amounts of about5 to 20 percent by weight of the starch-amine reaction product,preferably about 10 Suitable wetting agents include i percent by weightof the starch-amine reaction product. Glycerine has been found to beuseful in the size in order to make end-finding of the strand easier andto lessen the brittleness of the strand.

The combination of gelatin and polyvinyl alcohol in the size isdesirable because of the added film strength properties which thesematerials impart. The ratio of polyvinyl alcohol to gelatin when used incombination ranges from about 1:1 to 2:1. The combined amount of gelatinand polyvinyl alcohol in the size is about 0.1 to 0.2 percent by weightof the starch-amine reaction product.

Although the present invention has been described with respect tospecific details of certain embodiments thereof, it is not intended thatsuch details serve as limitations upon the scope of the invention exceptinsofar as set forth in the following claims.

We claim:

1. A method of forming glass fibers which comprises drawing glassfilaments from a molten supply of glass at a high rate of speed,gathering the filaments and combining them into a strand, applying anaqueous size to the filaments as they are being drawn, said size beingat an elevated temperature at the time of application and consistingessentially of an aqueous dispersion containing about 4 to 7 percent byweight of a starch-amine reaction product selected from the classconsisting of starchamine reaction products having the followingstructural formulae:

wherein X is starch, R is a radical selected from the group consistingof substituted alkyl, hydroxyalkyl, acyl, and aroyl radicals, and eachof R and R is a radical selected from the group consisting of hydrogen,alkyl, and aralkyl radicals, and

lsY

wherein X is starch, R is a radical selected from the group consistingof substituted alkyl, hydroxyl alkyl, acyl and aroyl radicals, and eachof R and R is a radical selected from the group consisting of hydrogen,alkyl and aralkyl radicals and where R, is a radical selected from thegroup consisting of hydrogen and alkyl radicals, and Y is a radicalselected from the group consisting of chloride, bromide and iodideradicals, about 25 to 70 percent by weight of a lubricant based upon theweight of the starchamine reaction product and an efifective amount of afungicide, said size having a viscosity of about 1 to 20 centipoises at20 C., winding the sized strand on a rapidly rotating forming tube andconditioning the strand wound on the forming tube to reduce the moisturecontent of the strand to that amount which is acceptable for twistingthe strand into yarn on conventional textile twisting apparatus.

2. The method as described in claim 1 wherein the size contains 8 to 13percent by weight of a Wetting agent based upon the weight of thelubricant and 4 to 15 percent by weight of a textile softener based uponthe weight of the starch-amine reaction product.

3. The method as described in claim 1 wherein the size contains 5 to 20percent by weight of a plasticizer for the starch-amine reaction productbased upon the Weight of the starch-amine reaction product.

4. The method as described in claim 1 wherein the size contains about0.1 to 0.2 percent by weight of gelatin and polyvinyl alcohol, basedupon the weight of the starchamine'reaction product, with the Weightratio of polyvinyl alcohol to gelatin ranging from about 1:1 to 2:1.

5. The method as described in claim 1 wherein the size contains 8 to 13percent by weight of a wetting agent based upon the Weight of thelubricant, 4 to 15 percent by weight of a textile softener based uponthe Weight of the l 1 starch-amine reaction product, 5 to 20 percent byWeight of a plasticizer for the starch-amine reaction product based uponthe weight of the starch-amine reaction product and 0.1 to 0.2 percentby Weight of gelatin and polyvinyl alco hol based upon the weight of thestarch-amine reaction product, with the Weight ratio of polyvinylalcohol to gelatin ranging from about 1:1 to 2:1.

6. A strand produced according to the method of claim 1.

7. A strand produced according to the method of claim 2.

8. A strand produced according to the method of claim 3.

9. A strand produced according to the method of claim 4.

- 10. A strand produced according to the method of claim 5.

References Cited in the file of this patent UNITED STATES PATENTS

1. A METHOD OF FORMING GLASS FIBERS WHICH COMPRISES DRAWING GLASSFILAMENTS FROM A MOLTEN SUPPLY OF GLASS AT A HIGH RATE OF SPEED,GATHERING THE FILAMENTS AND COMBINING THEM INTO A STRAND, APPLYING ANAQUEOUS SIZE TO THE FILAMENTS AS THEY ARE BEING DRAWN, SAID SIZE BEINGAT AN ELEVATED TEMPERATURE AT THE TIME OF APPLICATION AND CONSISTINGESSENTIALLY OF AN AQUEOUS DISPERSION CONTAINING ABOUT 4 TO 7 PERCENT BYWEIGHT OF A STARCH-AMINE REACTION PRODUCT SELECTED FROM THE CLASSCONSISTING OF STARCHAMINE REACTION PRODUCTS HAVING THE FOLLOWINGSTRUCTURAL FORMULAE: X-O-R-N(-R1)-R2 WHEREIN X IS STARCH, R IS A RADICALSELECTED FROM THE GROUP CONSISTING OF SUBSTITUTED ALKYL, HYDROXYALKYL,ACYL, AND AROYL RADICALS, AND EACH OF R1 AND R2 IS A RADICAL SELECTEDFROM THE GROUP CONSISTING OF HYDROGEN, ALKYL, AND ARALKYL RADICALS, ANDX-O-R-N(-R1)(-R2)-R3-Y WHEREIN X IS STARCH, R IS A RADICAL SELECTED FROMTHE GROUP CONSISTING OF SUBSTITUTED ALKYL, HYDROXYL ALKYL, ACYL ANDAROYL RADICALS, AND EACH OF R1 AND R2 IS A RADICAL SELECTED FROM THEGROUP CONSISTING OF HYDROGEN, ALKYL AND ARALKYL RADICALS AND WHERE R3 ISA RADICAL SELECTED FROM THE GROUP CONSISTING OF HYDROGEN AND ALKYLRADICALS, AND Y IS A RADICAL SELECTED FROM THE GROUP CONSISTING OFCHLORIDE, BROMIDE AND IODIDE RADICALS, ABOUT 25 TO 70 PERCENT BY WEIGHTOF A LUBRICANT BASED UPON THE WEIGHT OF THE STARCHAMINE REACTION PRODUCTAND AN EFFECTIVE AMOUNT OF A FUNGICIDE, SAID SIZE HAVING A VISCOSITY OFABOUT 1 TO 20 CENTIPOISES AT 20*C., WINDING THE SIZED STRAND ON ARAPIDLY ROTATING FORMING TUBE AND CONDITIONING THE STRAND WOUND ON THEFORMING TUBE TO REDUCE THE MOISTURE CONTENT OF THE STRAND TO THAT AMOUNTWHICH IS ACCEPTABLE FOR TWISTING THE STRAND INTO YARN ON CONVENTIONALTEXTILE TWISTING APPARATUS.
 6. A STRAND PRODUCED ACCORDING TO THE METHODOF CLAIM 1.